The present invention relates to a head-mounted image display device, or more particularly, a head-mounted image display device for use in viewing an image displayed on an image display element.
In recent years, various types of head-mounted image display devices have been proposed to enable a user to readily enjoy a large-size image. The present inventor has commercialized a head-mounted image display device that employs a free-form surface prism so as to be lightweight and offer high image quality.
The head-mounted image display device is connected to an image source, for example, a television, a video player, or a DVD player, thus receiving a video signal or an audio signal from the image source. An LCD and an optical system incorporated in the head-mounted image display device projects an image on user""s eyes. Moreover, earphones that are an accessory are used to radiate sounds to the user""s ears.
Various head-mounted image display devices have been proposed to be adopted as a display device that is used with, for example, a personal computer, a word processor, or any other office automation equipment and that displays images.
Furthermore, the head-mounted image display device falls into a type of displaying an image on user""s eyes and a type of displaying an image on either of the user""s right or left eye. Various proposals have been made for the latter type of displaying an image on one of user""s eyes.
For example, Japanese Patent Unexamined Publication No. 4-58212 describes a display for office automation (OA) equipment. The display consists mainly of an image projector, a light path deflecting member, and a head-mounted member. The light path deflecting member is positioned to conduct light, with which an image is displayed and which is emitted from the image projector, in a predetermined direction. The head-mounted member bears the image projector and light path deflecting member. The image projector consists mainly of an optical image display means and an optical member. The optical image display means has a display surface on which an image is displayed according to an output signal of a main unit of the OA equipment. The optical member projects light, with which an image is displayed and which is emitted from the display surface, to the light path deflecting member. The display is designed to maintain a proper distance between the eye and a display image.
Moreover, Japanese Patent Unexamined Publication No. 10-74051 describes a head-mounted display device having an image display means and a holding means. The holding means can be worn on an observer""s head while holding the image display means. The head-mounted display device introduces light; with which an image is displayed and which is emitted from the image display means, to one of the observer""s eyes. The holding means can hold the image display means while being worn on either the right region of the head or the left region thereof.
Japanese Patent Unexamined Publication No. 10-123455 describes a head-mounted display device having an image display means and a holding means that holds the image display means and can be worn on an observer""s head. The image display means includes a means for emitting light, with which an image is displayed, to a point in front of an observer, an arm that is extended forwards from one side of the observer, and an optical element attached to the front end of the arm. The head-mounted display device uses the optical element to change the light path of the light, with which an image is displayed, and thus introduces the light to the observer""s eye. The optical element is coupled to the arm so that it can be displaced in order to escape from extraneous force that works on the optical element from forward.
Japanese Patent Unexamined Publication No. 10-75408 describes a head-mounted display device having an image display means and a holding means that holds the image display means and that can be worn on an observer""s head. The holding means includes a supporting member and at least four pad members that are coupled to the supporting member. The supporting member can be elastically deformed so that the pad members can apply elastic force to back and front parts on the right region of the observer""s head and back and front parts on the left region thereof, and can thus press the back and front parts.
Japanese Patent Unexamined Publication No. 10-39784 describes a head-mounted display device having a means for emitting light with which an image is displayed, a light path changing means, and a holding means. The light path changing means is located in front of an observer. The holding means holds the means for emitting light with which an image is displayed and the light path changing means and can be worn on the observer""s head. The light path changing means can change the light path of the light with which an image is displayed so that a virtual image of an object of observation will be formed in front of the observer. The means for emitting the light with which an image is displayed and the light path changing means are coupled to the holding means so that they can be moved together over the spherical surface of the holding means. The center of the spherical surface is aligned with a position that is closer to the observer than to the light path changing means.
Japanese Patent Unexamined Publication No. 8-305298 describes a head-mounted display device that is worn on an observer""s head and that has an image display unit and a head-mounted holder which holds the display unit. When the head-mounted display device is worn on an observer""s head, if the observer""s line of sight is aligned with a front direction, an image is displayed outside a field-of-view range on the display unit. If the observer""s line of sight is aligned with any direction other than the front direction, an image is displayed within the field-of-view range on the display unit. If the observer""s line of sight is aligned with the front direction, the components of the head-mounted display device are brought to substantially outside the field-of-view range.
Japanese Patent Unexamined Publication No. 8-320453 describes a display device that is worn by an observer and has an image display unit and a holder for holding the display unit. An image-displayed position can be changed within an observer""s discernible range.
In recent years, personal computers that enable a user to enter sentences or operation commands by voice have been put on the market. For example, a user wears a microphone-inclusive headphone or the like on the user""s head so as to enter voice.
The microphone-inclusive headphone has right and left headphones linked by, for example, a headband. An arm is extended from the side surface of one of the headphones, and a microphone is fixed to the distal end of the arm.
The foregoing microphone-inclusive headphone has the a microphone thereof located in front of the user""s mouth using the arm thereof. The arm therefore extends in front of the user""s face. Since the headphone is large in size, the headphone may be hard to handle or may be worn uncomfortably. The adaptation of the structure, which has the microphone attached to the arm, to a head-mounted image display device as it is cannot always be said to be the best.
Moreover, a viewer that displays an image and projects it on a user""s eye must maintain a predetermined positional relationship relative to the eye despite a little movement of the head. If the positional relationship is maintained insufficiently, an image to be observed may fluctuate or a distance from an eye may change. This causes a user to feel uncomfortable. A technology for reliably bearing the viewer relative to the eye is therefore needed.
Accordingly, an object of the present invention is to provide a head-mounted image display device that is compact and can be worn comfortably.
According to a first aspect of the present invention, there is provided a head-mounted image display device having a viewer located in front of a user""s eye so as to make an image viewable. The viewer includes an image display element, an optical system, and a frame member. The optical system conducts an image, which is displayed on the image display element, so that the image can be viewed. The frame member bears the image display element at a predetermined position relative to the optical system. The head-mounted image display device has a microphone, which converts voice into an electric signal, mounted on the frame member.
According to a second aspect of the present invention, the head-mounted image display device in accordance with the first aspect may be disposed opposite the user""s right eye so that an image displayed on the viewer can be viewed with the right eye or may be disposed opposite the user""s left eye so that the image can be viewed with the left eye. The microphone is mounted on the frame member so that depending on whether the head-mounted image display device is disposed opposite the user""s right eye or left eye, the microphone will be located at either of substantially symmetric positions on the user""s head and will be separated from the user""s mouth by substantially the same distance.
According to a third aspect of the present invention, there is provided a head-mounted image display device having a viewer located in front of a user""s eye so as to make an image viewable. The viewer includes an image display element, an optical system that conducts an image, which is displayed on the image display element, so that the image can be viewed, and a frame member that bears the image display element at a predetermined position relative to the optical system. The head-mounted image display device further includes a supporting member that contacts a user""s face to support the viewer so that the viewer will have a predetermined positional relationship to the user""s eye.
According to a fourth aspect of the present invention, in the head-mounted image display device in accordance with the third invention, the supporting member is made of an elastic material. This is intended that the, supporting member can alleviate pressure which occurs when the supporting member contacts the user""s face, and the supporting member can elastically deform in conformity with the shape of a region of the user""s head which the supporting member contacts.
According to a fifth aspect of the present invention, in the head-mounted-image display device in accordance with the fourth aspect, the supporting member is shaped to contact a region of a user""s face in which a bone lies subcutaneously close to the skin.
According to a sixth aspect of the present invention, in the head-mounted image display device in accordance with the fifth aspect, the supporting member is shaped to contact a region in which at least one of the nasal bone, cheekbone, and superior ocular bone lies subcutaneously close to the skin.
According to a seventh aspect of the present invention, in the head-mounted image display device in accordance with the fourth aspect, the supporting member is formed substantially covering along the perimeter of the viewer in order to block the gap between the viewer and a user""s eye.
According to an eighth aspect of the present invention, in the head-mounted image display device in accordance with the third aspect, the supporting member covers the optical system and has a portion thereof shaped not to interfere with viewing of an image or scenery conducted by the optical system.
According to a ninth aspect of the present invention, there is provided a head-mounted image display device having a viewer located in front of a user""s eye so as to make an image viewable. The viewer includes an image display element, an optical system, and a frame member. The optical system conducts an image, which is displayed on the image display element, so that the image can be viewed. The frame member bears the image display element at a predetermined position relative to the optical system. The head-mounted image display device further includes an electric circuit board for a display element, an illuminating member, an electric circuit board for illumination, and a connector. The electric circuit board for a display element has the image display element mounted thereon. The illuminating member illuminates the image display element. The electric circuit board for illumination has the illuminating member mounted thereon. The connector connects the electric circuit board for a display element and the electric circuit board for illumination to each other so as to be able to disconnect the electric circuit boards each other.
According to a tenth aspect of the present invention, in the head-mounted image display device in accordance with the ninth aspect, the electric circuit board for illumination is held in the frame member or an illuminating member-fixing member that is fixed in the frame member. The surface of a portion of the frame member or fixing member that holds the electric circuit board for illumination is formed as a diffusing/reflecting surface that homogenizes and reflects light emanating from the illuminating member.
According to an eleventh aspect of the present invention, there is provided a head-mounted image display device having a viewer located in front of a user""s eye so as to make an image viewable. The viewer includes an image display element, an optical system, and a frame member. The optical system conducts an image, which is displayed on the image display element, so that the image can be viewed. The frame member bears the image display element at a predetermined position relative to the optical system. The frame member bears the image display element so as to at least substantially seal the image display element. Thus, the viewer is substantially sealed.